Lab 7: Aerobic Cellular Respiration

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Lab 7 Aerobic Cellular Respiration
Pea plants Zophobus morio larvae
http//www.astronomynotes.com/nature/spr06flowers/
red/red3.jpg AND http//aqualandpetsplus.com/Live
20F222.jpg
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I. Cellular Respiration (Intro)

• Cells require ATP in order to function.
• Cellular respiration is the metabolic machinery
  that releases energy from food molecules.

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I. Cellular Respiration Anaerobic vs. Aerobic
Anaerobic Respiration (ex. fermentation, lactic
acid fermentation) does not require oxygen for
the production of ATP.
Aerobic Respiration requires oxygen for the
production of ATP.
Certain organisms can perform both Anaerobic and
Aerobic respiration depending on the availability
of Oxygen.
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I. Cellular Respiration Anaerobic vs. Aerobic
Certain organisms can perform both Anaerobic and
Aerobic respiration depending on the availability
of Oxygen.
Yeast Cells can perform aerobic respiration or
alcoholic fermentation Human Muscle Cells can
perform aerobic respiration OR when starved for
oxygen, as in during vigorous exercise, muscle
cells can switch to producing ATP by lactic acid
fermentation (cause of lactic acid buildup).
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I. Cellular Respiration Anaerobic vs. Aerobic
Yeast Cells, in the absence of oxygen can
produce ATP by alcoholic fermentation.
Human Muscle Cells, when starved for oxygen as in
during vigorous exercise, can switch to producing
ATP by lactic acid fermentation (cause of lactic
acid buildup).
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II. Aerobic Respiration Whole Organism

• Aerobic respiration at the whole organism level
  process by which gases are exchanged with the
  environment.

O2
CO2
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II. Aerobic Respiration Whole Organism

• Respiratory Surface ( part of the organism where
  O2 diffuses into and CO2 diffuses out of the
  organism) must be moist, as gases must be
  dissolved in water before they can diffuse in or
  out.

http//www.go-epix.net/uploadedimages/Water20drop
20ks16870208050114134057.JPG
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II. Aerobic Respiration Whole Organism
In unicellular aquatic protozoans O2 dissolved
in water passes across the cell membrane by
diffusion, and CO2 exits.
CO2
O2
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II. Aerobic Respiration Whole Organism
In multicellular aquatic plants and invertebrate
animals O2 dissolved in water enters cells by
diffusion, and CO2 exits by diffusion.
Planarian
CO2
O2
Elodea cell
http//www.cdb.riken.jp/jp/04_news/img/planarian30
0.jpg
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II. Aerobic Respiration Whole Organism
In insects O2 enters through small openings in
the body wall (spiracles) and is carried through
tracheal tubes to moist cell membranes, across
which respiratory exchange occurs.
Spiracles
spiracle
SEM
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II. Aerobic Respiration Whole Organism
In fish O2 (in H2O) diffuses across the surface
of gills, into capillaries of the circulatory
system and CO2 diffuses in the opposite direction.
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II. Aerobic Respiration Whole Organism
In terrestrial vertebrates O2 diffuses across
moist epithelial cells in the internal alveoli of
the lungs. CO2 diffuses in the opposite direction.
O2
CO2
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II. Aerobic Respiration Whole Organism
In multicellular terrestrial flowering plants O2
(in H2O) diffuses across the surface of roots and
stems, and CO2 diffuses in the opposite
direction. Leaves possess specialized cells
(guard cells) which open and close stomates,
regulating gas exchange.
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II. Aerobic Respiration Cellular

• Cells of most organisms, including plants, carry
  out aerobic cellular respiration 24 hours per day.

60 of energy from glucose is trapped in ATP
Glucose
40 of energy from glucose is lost as
heat Endothermic animals use this heat for
regulating body temperature
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II. Aerobic Respiration Cellular

• To measure the rate of respiration one can either
  1) measure the rate of reactants consumed, or
  2) measure the rate of products produced.

products produced
reactants consumed
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II. Aerobic Respiration Cellular
Glycolysis
1
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II. Aerobic Respiration Cellular
Glycolysis
1

• enzyme catalyzed
• energy releasing
• takes place in cell cytoplasm (prokaryotic and
  eukaryotic cells)

C6H12O6 2 Pyruvic acid molecules 2 NADH
2 ATP
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II. Aerobic Respiration Cellular
Glycolysis
1
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II. Aerobic Respiration Cellular
Preparation step
2
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II. Aerobic Respiration Cellular
Preparation step
1

• occurs in fluid matrix of mitochondria
  (eukaryotic organisms)

2 Pyruvic acid mols CO2 NADH 2 Carbon
compounds
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II. Aerobic Respiration Cellular
Preparation step
2
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II. Aerobic Respiration Cellular
Krebs Cycle
3
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II. Aerobic Respiration Cellular
Krebs Cycle
1

• enzyme catalyzed
• occurs in fluid matrix of mitochondria
  (eukaryotic organisms)

2 Carbon Compound CO2 ATP FADH2
NADH Acetyls
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II. Aerobic Respiration Cellular
Krebs Cycle
3
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II. Aerobic Respiration Cellular
E- transport and Chemiosmosis
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II. Aerobic Respiration Cellular
E- transport and Chemiosmosis
1

• electrons from NADH and FADH2 pass through a
  series of compounds and loose energy.
• some energy is lost as heat
• most of the energy is trapped at ATP through the
  process of chemiosmosis
• occurs in cristae of the mitochondria
  (eukaryotes) or folds of the cell membrane
  (prokaryotes).

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II. Aerobic Respiration Cellular
E- transport and Chemiosmosis
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